Arithmetic Slices 2
hard
1. You are given an array(arr) of integers. 2. You have to find the count of arithmetic slices in the given array. 3. Arithmetic slice is defined as the sub-sequence of an array having all its elements in A.P and length of sub-sequence should be greater than or equal to 3.
Constraints
1 <= N <= 1000 -10^8 <= arr[i] <= 10^8
Format
Input
A number N arr1 arr2.. N numbers
Output
Check the sample output and question video.
Example
Sample Input
4
1
2
3
4
Sample Output
3